I've never done any coating, however there is a major difference between glass, UHMW plastic, and Delrin. The difference is glass is microscopically porous, where the plastics are not, and actually slippery. I use both plastics for woodworking jigs and fixtures. I'm no chemist, so I couldn't tell the specifics, but both have an apparant self-lubricating property, that allows other materials to slide along them with relative ease,like they are lubed. That being said, the pores on glass give a cling factor the other materials dont have. So the only thing left to do is what Photo Engineer said, try it and see.

Rick